JPH0320618B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicular continuously variable transmission for a horizontal engine using a V-belt type continuously variable transmission.

[Prior Art] When a vehicle is equipped with a continuously variable transmission for a horizontal engine in which the engine is placed horizontally with respect to the vehicle body, the continuously variable transmission is connected to the input shaft, output shaft, counter shaft, differential shaft, etc. There are four shafts, such as a shear shaft, which are advantageous in terms of freedom of mounting the continuously variable transmission to the engine and vehicle body because the axial dimension is shortened, but the configuration becomes complicated. There is a drawback. On the other hand, there are continuously variable transmissions that are constructed from two shafts, an input shaft and an output shaft, but the main constraints that must be taken into consideration are the following three points as shown in FIG.

a) Engine 100 and vehicle continuously variable transmission 10
The position of the mounting surface A of No. 1 is within a certain range from the center line E.

b) A mechanism disposed on the first shaft (the input shaft of the V-belt continuously variable transmission and a shaft coaxial therewith) within the distance B between the mounting surface A and the body side member 102 performs maintenance. It should fit comfortably enough that it can be easily done.

c) Position of center line E and one constant velocity joint 1
03 and the distance D to the other constant velocity joint 104 are equal.

Conventionally, this type of continuously variable transmission for a vehicle has a V-belt type continuously variable transmission mechanism connected to the other constant velocity joint 104, as shown in Japanese Patent Laid-Open No. 57-29845, for example.
The damper and flywheel 1 are placed between the input pulley 105 and the engine 100.
06, and a second shaft (output shaft of the V-belt continuously variable transmission and a shaft having a coaxial center therewith) 1
20 has two wet brakes for starting, one for forward and one for reverse.
There is one.

[Problems to be Solved by the Invention] However, in the above-mentioned continuously variable transmission, a wet brake is provided as a starting device at the rear of the output shaft, which is the second shaft of the V-belt continuously variable transmission.
The transmission torque is large at the time of starting (half-clutch state), and a large heat capacity of the brake is required. For this reason, the number of discs in the wet brake increases, the axial dimension increases, and the distance C from the center line E to one constant velocity joint 103 increases.
There is a problem that the forces acting on the two constant velocity joints 103 and 104 become unbalanced, and due to this increase in size, the constant velocity joints disposed adjacently on the second shaft of the continuously variable transmission Since the distance from the wheel to the wheel is shortened, a problem arises in that it cannot be mounted on a vehicle with a small vehicle body in the width direction due to limitations on the joint angle of the constant velocity joint.

To solve this problem, in order to shorten the axial dimension on the second shaft 120, the starting friction engagement device is
It is conceivable to arrange it on the shaft 110 and connect it between the engine 100, which has a small transmission torque, and the input pulley 105.

However, the starting friction engagement device is
and the input pulley 105, the distance between the engine mounting surface A and the input pulley 105 becomes large. The problem is that the distance is shortened and the ease of mounting is not improved.

In addition, the friction engagement device for starting is connected to the input pulley 105.
If the friction engagement device is disposed on the opposite side of the engine 100, the diameter of the friction engagement device must be made small to prevent interference with the drive shaft connected via the constant velocity joint 104. The axial dimension of the device is extended. Therefore, the first shaft 11 of the continuously variable transmission
The axial dimension of 0 increases, and there is a risk of interference with the side member 102 of the body.

The present invention solves the above problems, and includes:
In a continuously variable transmission for vehicles that consists of two shafts, the axial dimension on the second shaft is shortened, and the axial dimension from the mounting surface of the continuously variable transmission to the engine to the end surface of the output pulley on the opposite side of the engine is reduced. The purpose of the present invention is to provide a continuously variable transmission for a vehicle that has a shortened length and is thereby capable of securing a sufficient axial length between a constant velocity joint and a wheel, and has excellent mountability. .

[Means for Solving the Problems] To this end, the continuously variable transmission for a vehicle of the present invention includes an input pulley having a hollow portion and whose effective diameter is variable by a servo mechanism; A continuously variable transmission consisting of an output pulley that is arranged in parallel and whose effective diameter is variable by a servo mechanism, and a V-belt that transmits power between the input pulley and the output pulley; a differential mechanism having a first drive shaft disposed and extending toward the engine, and a second drive shaft passing through a hollow portion of the output pulley and extending toward the opposite side of the engine; and the output pulley and the differential a forward/reverse switching mechanism concentrically connected to the mechanism; a rod disposed in a hollow part of the input pulley passing through the input pulley; and a rod disposed on the opposite side of the input pulley from the engine. an operating section for arbitrarily moving the rod in the axial direction; and an operating section disposed between the input pulley and the engine for selectively connecting the input pulley and the output shaft of the engine in accordance with the axial movement of the rod. It is characterized by comprising a clutch mechanism having a frictional engagement part.

[Operation and Effects of the Invention] In the present invention, since the starting friction clutch mechanism is connected between the engine output shaft, which has a small transmission torque, and the continuously variable transmission mechanism, the starting friction clutch mechanism is connected to the second shaft, which has a large transmission torque. The axial dimension on the second shaft is shortened compared to those provided with an engagement device, and
The frictional engagement portion can be configured to have a small heat capacity.

In addition, since the friction engagement part of the starting friction clutch mechanism is disposed between the input pulley and the engine, the friction engagement part can be constructed with a large diameter, and the heat capacity of the friction engagement part can be reduced. In addition to being small, the axial dimension of the frictional engagement portion can be made small.

Furthermore, the friction engagement part of the friction clutch mechanism is remotely controlled by an operating part disposed on the opposite side of the input pulley from the engine through the hollow part of the input pulley. Since the component of the clutch mechanism disposed between the input pulley and the clutch mechanism is only the above-mentioned axially short frictional engagement portion, the distance between the engine and the input pulley can be made small. Thereby, the axial length from the mounting surface of the continuously variable transmission to the engine to the end surface of the output pulley on the opposite side of the engine can be shortened.

Therefore, it is an object of the present invention to provide a continuously variable transmission that can secure sufficient axial length between a constant velocity joint and a wheel and has excellent mountability even in a vehicle with a small vehicle body in the width direction. Can be done.

[Example] Next, the present invention will be explained based on an example shown in FIG.

1 is an engine, 10 is a transmission case, 11 is an output shaft of the engine, 12 is a flywheel fastened to the tip thereof, 2 is a V-belt type continuously variable transmission, and 3 is a clutch mechanism. A plate type dry friction clutch is used. 4 is a forward/reverse switching mechanism, and 5 is a differential mechanism.

The flywheel 12 consists of a disk 123 whose center part is fastened to the end face 111 of the engine output shaft 11 with a bolt 121, and an annular weight 125 fastened to the outer periphery of the disk 123. A cylindrical portion 127 for forming a clutch room inside extends on the other side (the same applies hereinafter), and an inner peripheral edge 129 for forming a clutch surface 128 at the other end of the cylindrical portion 127. is formed.

The V-belt continuously variable transmission 2 includes a hollow input shaft 21 arranged in series coaxially with the engine output shaft, and a hollow V-belt continuously variable transmission arranged parallel to the input shaft. an output shaft 22, an input pulley 23 provided on the input shaft 21, an output pulley 24 provided on the hollow output shaft 22, and a V-belt 2 that transmits power between the input pulley 23 and the output pulley 24.
5. It consists of a servo mechanism 26 that changes the effective diameter of the input pulley 23, a servo mechanism 27 that changes the effective diameter of the output pulley 24, and a cam mechanism 28 provided on the input pulley.

The input shaft 21 has a hollow shaft center and a bearing 2.
11 and 212 to be rotatably supported by the V-belt type continuously variable transmission case 10, and an alligator stage 213 is formed on one side of the engine, and an outer peripheral spline 214 and a tip screw 215 are formed on the other side.

The output shaft 22 has a hollow shaft center, and in this embodiment, is formed integrally with a sleeve of a fixed flange, which will be described later, and is rotatably supported by the V-belt type continuously variable transmission case 10 by bearings 221 and 222.

The input pulley 23 has one end (the right end in the figure) connected to the stage 21 of the input shaft via a thrust bearing 216.
3, and an outer circumferential spline 23 on the outer periphery of the other end.
1 and a sleeve-shaped portion 23 provided with a keyway 232
3, and a slit 234 formed integrally with the sleeve-shaped portion 233 and on the outer periphery for detecting the rotational speed of the input shaft.
A fixed flange 23A consisting of a flange portion 235 provided around the fixed flange 23A, a key groove 236 that is fitted onto the sleeve portion 233 of the fixed flange 23A so as to be freely displaceable in the axial direction, and that corresponds to the key groove 232 of the fixed flange on the inner peripheral wall. A movable flange 23B consisting of a sleeve-shaped hub portion 278 in which a driven screw 237, which is a first screw, is formed on the outer peripheral wall thereof, a flange portion 239 formed integrally with the hub portion 278, and a key. A fixed flange 23A and a movable flange 23B are inserted into grooves 232 and 236.
It consists of a ball key 230 that allows displacement in the axial direction and integrally rotates around the axis.

The output pulley 24 has a keyway 241, a spline 242, a screw 243, and a spline 2 on the outer periphery.
A fixed flange 24A consisting of a sleeve-shaped part 244 formed integrally with the output shaft 22 and a flange part 245 formed integrally with the sleeve-shaped part 244, and a sleeve part 244 of the fixed flange 24A. A key groove 2 is fitted on the outside so as to be freely displaceable in the axial direction, and a key groove 2 corresponding to the key groove 241 is provided on the inner periphery.
450, and a sleeve-shaped hub portion 247 having a driven screw 246, which is a first screw, formed on the outer periphery.
A movable flange 24B consisting of a flange portion 248 formed integrally with the hub portion 247, and a movable flange 24B that is inserted into key grooves 241 and 2450 to allow displacement in the axial direction of the fixed flange 24A and movable flange 24B. It consists of a ball key 240 for integrally rotating.

The V-belt 25 is connected to the input pulley 23, respectively.
and working surfaces 251 and 252 that contact the V-shaped working surfaces formed by the fixed flange 23A, fixed flange 24A, movable flange 23B, and movable flange 24B of the output pulley 24 to form a friction surface.
are provided on both sides.

The input pulley servo mechanism 26 has a drive screw 261 formed on the inner periphery, which is a second screw that is screwed into the driven screw 237 of the movable flange 23B of the input pulley, and one end is connected to a cam (described later) via a frustration bearing 265. A sleeve 262 that is a driver of a movable flange that is in contact with the other cam race 287 of the mechanism, a wet multi-plate electromagnetic downshift brake 263 that is provided between the sleeve 262 and the case 10 and brakes the sleeve 262, and a sleeve. 26
A cylindrical spring guide 26 arranged on the outer periphery of 2
4. The spring guide 264 and sleeve 262
A first upshift torsion coil spring 26 is arranged between the engine and the movable flange 23B, and has one end connected to the engine, and the other end connected to the other end of a cylindrical spring guide 264.
6. A second upshift torsion arranged around the outer periphery of the spring guide, whose engine side end is connected to the engine side end of the spring guide 264 and whose other side end is connected to the other side end of the sleeve 262. It consists of a coil spring 267.

The output pulley servo mechanism 27 includes a sleeve 272, which is a driver, and a sleeve 272, which is a driver, on the inner circumference of which a drive screw 271, which is a second screw that is screwed into the driven screw 246 of the movable flange 24B, is formed, and the sleeve 272 and the case 10. a wet multi-plate electromagnetic upshift brake 273 that fixes the upshift, a torsion coil spring 274 for downshift connected with both ends connected between the sleeve 272 and the movable flange 24B, and a spline 242 of the output shaft. A spline is formed to fit into the movable flange 24B.
One side is in contact with the end face of the sleeve 272 via the bearing 275, and the other side is in contact with the nut 276 via the inner race of the bearing 221.
and a support ring 277 that supports the sleeve 272 in the axial direction.

The cam mechanism 28 is connected to the input shaft 2 as shown in FIG.
The inner peripheral spline 281 is fixed in the axial direction by a snap ring 218 externally fitted on the input shaft 21 and a nut 217 screwed onto the screw 215 formed at the end of the input shaft. One cam race 282 formed, the other cam race 287, a tapered roller 288 interposed between these cam races, and a cover ring 2 of the roller 288.
89, the roller 288 has a race 282
The movable flange 23B is sandwiched between the working surfaces 292 and 286 of the movable flange 23A, and changes the pressing force that presses the movable flange 23B in the right direction in the figure in response to the rotational displacement of the input shaft 21 and the fixed flange 23A.

Next, the operation of this V-belt type continuously variable transmission will be explained.

(a) When driving at constant speed, both brakes 263 and 273 are released.

Torque is transmitted through the input shaft 21 → one race 282 of the cam mechanism → tapered roller 288 → the other race 287 → input pulley 23 → V belt 2
5→output pulley 24→output shaft 22. The magnitude of the torque transmitted by the V belt 25 is V
The clamping force is proportional to the clamping force applied to the belt 25, and the clamping pressure is brought into contact with the other cam race 287 via the movable pulley 23B and the sleeve 262 screwed with the movable pulley, and due to the principle of the cam mechanism, the input pulley is rotated in the rotation direction. The clamping force Fc that moves slightly and acts in the axial direction by the tapered roller 288 changes in proportion to the transmitted torque as shown in FIG. , and thereby V
The surface pressure between the working surface of the belt 25 and the working surfaces of the movable flange 23B and the fixed flange 23A changes, thereby changing the clamping force on the contact surfaces. In Fig. 4, F1 is the required clamping pressure at which the V-belt does not slip at the maximum reduction ratio, F2 is the required clamping pressure at which the V-belt does not slip at the minimum reduction ratio, and F0 is the required clamping pressure at which the V-belt does not slip at the minimum reduction ratio. The clamping pressure, Fs, indicates the clamping pressure due to the spring. As shown by Fc in the graph of Fig. 4, in the V-belt continuously variable transmission using the cam mechanism 28, the clamping pressure and the transmitted torque are directly proportional even if the transmitted torque is 5 kg or less, and unnecessary clamping between the V-belt and the pulley is avoided. It can be seen that the generation of pressure can be reduced.

(b) Upshifting is performed by engaging the brake 273.

FIG. 2 shows the state of the maximum reduction ratio when the continuously variable transmission has been downshifted. In this state, the first and second upshift torsion coil springs 266 and 267 of the input pulley servo mechanism 26 are As the input pulley 23 is twisted, energy is accumulated, and a force is applied that pushes the movable flange 23B of the input pulley 23 to the right in the figure.

When the brake 273 is engaged, the sleeve 272
Since the drive screw 271 is fixed, the driven screw 246 formed in the sleeve portion 247 of the movable flange 24B rotates along the drive screw 271, and the movable flange 24B rotates in a direction (to reduce the effective diameter of the output pulley 24). On the other hand, the movable flange 23B is displaced toward the first and second upshift torsion coil springs 266 and 2.
67 causes the input pulley 23 to be displaced in a direction that increases its effective diameter (to the right in the figure), thereby performing an upshift. The brake 273 is released when the gear ratio reaches the control set value.

During this upshift, the torsion spring 274 of the servo mechanism of the output pulley is twisted and energy is stored.

(c) A downshift is performed by engaging the brake 263.

When the brake 263 is engaged, the sleeve 262 is fixed and the movable flange 23B is displaced in the direction of decreasing the effective diameter of the input pulley 23 (to the left in the figure), and the torsion spring 274 rotationally drives the sleeve 272 to return to the movable flange 24B. is displaced in the direction of increasing the effective diameter of the output pulley (to the left in the figure). This displacement of the movable flange 23B of the input pulley 23 is performed against the pressing force of the movable flange 23B by the cam mechanism. When the gear ratio reaches the control set value, the brake 263 is released. During this downshift, the first and second input pulley servo mechanisms 26
Upshift springs 266 and 267 are twisted to store energy.

In this V-belt type continuously variable transmission, if the electromagnetic brakes of the brakes 263 and 273 fail and the brakes become inapplicable, the vehicle can run with the gear ratio before the failure. Therefore, it is possible to prevent the gear ratio from being changed inadvertently as in the case of a V-belt continuously variable transmission in which the gear ratio is changed by a hydraulic servo due to oil pressure leakage, resulting in excellent safety.

The clutch mechanism 3 includes an engaging part 31 provided between the input pulley 23 and the engine 1, an operating part 33 provided on the other side of the input pulley for operating the engaging part 31, and a hollow space in the input shaft 21. It consists of a push rod 35 inserted into the. The engaging portion 31 is centered on the engine side end 3 of the push rod 35.
a diaphragm spring 313 arranged on the side of the engine in the clutch room; an annular pressure plate 315 engaged with the outer periphery of the diaphragm spring 313; A clutch plate 323 is disposed between the plate 315 and a clutch surface 128 provided on the annular weight 125 of the flywheel 12, and clutch disks 317 and 31 are attached to both sides of the clutch plate 323.
9. Input pulley 23 and diaphragm spring 3
13, and a hub 321 spline-fitted to the engine-side end 219 of the input shaft of the V-belt type continuously variable transmission at the center; It consists of a clutch plate 323 disposed therebetween, and a damper spring 325 connecting the hub 321 and the clutch plate 323. Operation unit 33
The push lever 331 is pivotally connected to the transmission case 10, the sliding cap 333 provided on the transmission case, the engine is in contact with the other end 352 of the push rod 35, and the other end is a release bearing. It consists of a bearing race 337 that is rotatably supported on the inner wall of the sliding cap 333 via a bearing race 335, and when the push lever 331 is driven to rotate in the counterclockwise direction in the figure around the fulcrum by manual or automatic operation, the sliding cap is rotated by the engine. The push lever 35 is pushed against the engine, and the diaphragm spring 31
Displace the center of the clutch plate 323 toward the engine and pull the pressure plate toward the engine to release the clutch plate 323 that was sandwiched between the first and second clutch disks 317 and 319 and fly it. The connection between the wheel 12 and the V-belt continuously variable transmission input shaft 21 is released.

The forward/reverse switching mechanism 4 includes a dog clutch 41 (brake device), a first simple planetary gear set 43, and a second simple planetary gear set 45.

The dog clutch 41 includes a fork 411 linked to an operating lever, a brake sleeve 413 that is engaged with the fork and slid in the axial direction, a first gear 415 (spline piece), a second gear 417 (spline piece), and a sleeve. 413
and a second gear 417.

The first planetary gear set 43 is a sun gear shaft 43 spline-fitted to the spline 249 provided on the output shaft 22 of the V-belt type continuously variable transmission.
a ring gear 433 connected to the second gear 417 of the dog clutch 41 and a sun gear 451 of the second planetary gear set 45;
The second planetary gear set 45 consists of a carrier 435 connected to the first gear 415 of the first gear and a second ring gear 453, and a planetary gear 437. The carrier 4 is spline-fitted to a spline 459 provided on an output sleeve 450 connected to the gearbox.
55 and a planetary gear 457. This forward/reverse switching mechanism 41 is configured to move forward at the set gear ratio when the sleeve 413 of the dog clutch 41 is engaged with the second gear 417 and the ring gear 433 and sun gear 451 are fixed to the case 101, either manually or automatically. is meshed with the first gear 415, and when the carrier 435 and the ring gear 453 are fixed to the case 10, a backward movement occurs at the set speed ratio.

The differential mechanism 5 has an output sleeve 450, which is the output shaft of the forward/reverse switching mechanism 4, as an input shaft. Large differential gears 55, 56 meshing with the small gears, one output shaft 57 spline-fitted to the large differential gear, the output shaft 22 of the V-belt continuously variable transmission, the first sun gear 431, and It consists of the other output shaft 58 inserted through the output sleeve 450.

13 and 14 are constant velocity joints provided at the ends of the output shafts 57 and 58 of the differential mechanism 5.

FIG. 5 shows another embodiment of the invention.

In this embodiment, hydraulic servos 2A and 2B are used for the servo mechanism of the input pulley 23 and the servo mechanism of the output pulley 24 as a V-belt type continuously variable transmission.
Forward/reverse switching mechanism 4, forward multi-plate brake 4B operated by hydraulic servo 4A, and hydraulic servo 4
It is equipped with a multi-disc brake 4D for reverse motion operated by C, and is equipped with an oil pump 6 as a hydraulic pressure source for these hydraulic servos.

By placing the engaging part of the clutch mechanism next to the engine of the input pulley of the V-belt continuously variable transmission, and placing the operating part on the side opposite to the engine, the axial dimension of the second shaft can be shortened. This allows one constant velocity joint to be set closer to the center, making it easier to ensure equal distances from each constant velocity joint to the wheels.

In addition, by using a dry single-plate clutch as the clutch, the engaging part can be compactly formed in a flyhole with a large heat capacity, and air cooling can be achieved by rotation of the clutch. Furthermore, this allows the axial dimension of the first shaft to be shortened. The distance between the end of the first shaft opposite to the engine and the body is large, allowing for excellent mounting ease and a small turning radius of the vehicle. Further V
By using the servo mechanism of the belt type continuously variable transmission with an electromagnetic brake and torsion spring,
Compared to the case where a hydraulic servo is used, the radial dimension can be made thinner, and by using a dog clutch for the engagement element of the forward/backward switching mechanism, the outer diameter of this part can also be made thinner, making it lightweight and compact. Furthermore, by adopting the above-mentioned dry clutch, dry servo mechanism, and dry dog clutch, the automatic transmission can be controlled without using hydraulic pressure, eliminating the need for a hydraulic control circuit due to hydraulic control, and eliminating the need for oil passage formation. can be simplified, manufacturing costs can be reduced, and maintenance can be facilitated. Furthermore, since the clutch, dog clutch, and electromagnetic brake can be easily operated both manually and automatically, control can be performed manually or automatically with the same configuration.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a state in which a continuously variable transmission for a vehicle is mounted on a vehicle, Fig. 2 is a sectional view of the continuously variable transmission for a vehicle according to the present invention, Fig. 3 is an enlarged view of the cam mechanism, and Fig. 4 is A graph for explaining the function of the cam mechanism, and FIG. 5 is a skeleton diagram of a continuously variable transmission for a vehicle according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Engine, 3... Clutch mechanism, 4... Forward/forward switching mechanism, 5... Differential mechanism, 21...
Input shaft, 23...input pulley, 24...output pulley,
25...V belt, 26, 27...servo mechanism, 28
...Cam mechanism, 23A, 24A...Fixed flange, 2
3B, 24B...Movable flange, 31...Engagement part, 3
3...Operation unit.

Claims (1)

[Scope of Claims] 1. An input pulley having a hollow part and whose effective diameter is variable by a servo mechanism, and an output having a hollow part and arranged in parallel to the input pulley and whose effective diameter is variable by a servo mechanism. a continuously variable transmission consisting of a pulley, and a V-belt that transmits power between the input pulley and the output pulley; a first drive shaft that is disposed concentrically on the engine side of the output pulley and extends toward the engine; a differential mechanism having a second drive shaft extending through a hollow portion to the opposite side of the engine; and a forward/reverse switching mechanism concentrically connected between the output pulley and the differential mechanism. a rod disposed in a hollow portion of the input pulley to pass through the input pulley; an operating section disposed on the opposite side of the input pulley from the engine for arbitrarily moving the rod in the axial direction; and the input pulley. The present invention is characterized by comprising a clutch mechanism disposed between the pulley and the engine and having a frictional engagement portion that selectively connects the input pulley and the output shaft of the engine in accordance with the axial movement of the rod. Continuously variable transmission for vehicles. 2. The continuously variable transmission for a vehicle according to claim 1, wherein the clutch mechanism is a dry single-plate friction clutch. 3. The continuously variable transmission for a vehicle according to claim 1, wherein the forward/reverse switching mechanism comprises first and second planetary gear sets and a dog clutch that selectively fixes the components thereof. Machine. 4. The input pulley and the output pulley have a fixed flange and a movable flange that is axially displaced relative to the fixed flange by the servo mechanism, and at least one of the input pulley and the output pulley has a a movable flange is axially coupled to the fixed flange via a cam mechanism;
The continuously variable transmission for a vehicle according to claim 1, wherein the clamping force between the fixed flange and the movable flange and the V-belt is made proportional to the V-belt transmission torque. 5. The servo mechanism includes a driver screwed onto the movable flange, a spring that rotates the driver, and a brake that brakes the driver. Continuously variable transmission for vehicles.